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Questions tagged [bluetooth-gatt]

The Generic Attribute Profile (GATT) defines the way that two Bluetooth Low Energy (BTLE) devices transfer data back and forth using concepts called Services and Characteristics.

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GattCallback error: 133 when writing a character to device?

I am getting a GattCallback error: 133 when writing data to the device.It happens, the app is in the background mode or killed state. using (IDevice _device = await adapter.ConnectToKnownDeviceAsync(deviceID, new ConnectParameters(false,…
John
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Convert byte array to string? ESP32 BLE firmware development

I am using an android app (mobile phone) and an ESP32, connected to each other via BLE. I am trying to send a string from the mobile phone to the ESP32. The android app sends a string in byte array form and the esp receives it. But I am having…
phantomBlurrr
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How to run GATT command in Android

I'm developing an Android application for read/write data for a BLE device. The specification of the device has mentioned one service UUID and two feature UUIDs. Service UUID: 0xFFF0 TX UUID: 0xFFF6, RX UUID: 0xFFF7 And bunch of command formats as…
Tharanga
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Read temperature from nRF 51822 bluetooth temperature sensor from Android phone

I have this bluetooth temperature sensor https://www.aliexpress.com/item/nRF51822-Bluetooth-4-0-BLE-SOC-Temperature-Atmospheric-Pressure-Acceleration-Sensor-Module-Gyroscope-Light-Sensor-MPU6050/32859423925.html?spm=a2g0s.9042311.0.0.e3534c4dT9GRz3…
maxxxo
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Unable to scan BLE after a while

My android app(react native app named "myApp") is scanning for BLE for 10 seconds in a loop(start - wait for 10 seconds - stop) I have noticed that after a while(something about 7 hours) my app can't find any device(although there is devices…
Daniel Piflaks
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Is it possible to automatically enable bluetooth connection of user's device after launching my web application?

I'm developing a web application (using node js and javascript) that needs to enable bluetooth connection of the device he/she is using before accessing the application. I've been looking for codes regarding to bluetooth enabling in web app but so…
mae tanaka
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readValue from characteristic always empty, but notifications work?

I'm using a bluetooth adapter with a scale, in a webapp using the bluetooth web API. I can grab a service and its characteristic, then call enableNotifications(), and set a callback for the 'characteristicvaluechanged' event. When I press "Print" on…
horatio13
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GATT_READ_NOT_PERMIT error when trying to use Android device as GATT server

I have an android application that has BLE GATT Server running so the android phone would be a peripheral device and other devices can connect to it. Sometimes the connections works fine, but very often when I try to pair the external device to the…
Radoslav Ignatov
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Combine keyboard & consumer control in descriptor

I have a hid_discriptor which looks like this: // from USB HID Specification 1.1, Appendix B.1 const uint8_t hid_descriptor_keyboard_boot_mode[] = { /* Keyboard */ 0x05, 0x01, // Usage Page (Generic Desktop) …
Gilles
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How to add an activity prior to the "BluetoothLeGatt" example?

As a newbie to programming, I took the Android Studio example code of "BluetoothLeGatt" and the whole project itself works as it should. However, when I try to add an activity (I added a java file where I correctly use an intent to open the first…
MMeier
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Wrong data sent while Bluetoothgatt.writecharacterstic

My android device is connected to a BLE dongle. The BLE Dongle is sending me messages for example A at 20 to 40 milliseconds of interval. I am getting messages in onCharacterticChange method. I am modifying the messages to for eg. to B. I am…
loop stack
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In BLE android app onCharacteristicRead is not calling even i have write bluetoothGatt.readCharacteristic(gattCharacteristic)

I'm developing an app to connect with BLE device and I'm following google developer guides. As per developer guide I have scanned BLE device and successfully establish connection with them and able to get available services and characteristics. Here…
YBDevi
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BLE Data lost on reading characteristic when the device sends data frequently

Android BLE Data lost on reading characteristic when the device sends data frequently. Byte Array converts from Big endian Every 4 bytes Make One Cell I should convert to decimal Here is my code: device.connectGatt(context, true, new…
Hossein Kurd
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which UUID should I use to read Characteristic from specific Bluetooth device?

which UUID should I use to read Characteristic from specific Bluetooth device? As far as I know, It doesn't need pairing, I have to connect to the device and receive data Is my code correct? Also mBluetoothGattService is null ! How I can receive…
Hossein Kurd
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Can we sneak BLE-Mesh-Device using BT packets log with WireShark and write the sniffed commands via nRFconnect App?

https://medium.com/@urish/reverse-engineering-a-bluetooth-lightbulb-56580fcb7546 Using the above link, I did try to hack and control a BLE Device which works in BLE-Mesh-Network, But it failed. Came here by looking for help to Know the possibility…
Linux Edwin K
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